Ulcer bacteria may protect against diarrhea

People who harbor ulcer-causing bacteria in their stomachs may be protected against some diarrheal diseases, suggests a new study.

The bacterium, called Helicobacter pylori, is especially common throughout the developing world, but only causes symptoms in a minority of those it infects.

People with chronic H. pylori infections are known to have an increased risk of stomach cancer and related diseases, but how infection is related to diarrheal diseases and the bacteria that cause them is still up for debate.

Dani Cohen, the lead author of the new report from Tel Aviv University in Israel, said that some previous studies have suggested that being infected with the ulcer-causing bacteria increases the risk of diarrhea, while others have reported finding the opposite.

So his team carried out a study in 595 male Israeli soldiers, close to one-third of whom visited a base clinic for diarrhea during their field training.

All of the soldiers had had their blood taken before the start of training, which researchers used to determine which men were chronically infected with H. pylori.